Periodontal disease is the principle oral complication of diabetes mellitus. Chlorhexidine gluconate is an oral antimicrobial mouthrinse that has been uses as a safe and effective agent in preventing and controlling plaque formation in selected populations. Since periodontal diseases are plaque-induced infections, the purpose of this study is to evaluate the effect of chlorhexidine gluconate mouthrinse on periodontal disease in patients with Type II diabetes. This study will also examine the relationships between diabetes control, medication compliance, and the efficacy of chlorhexidine mouthrinse on periodontal disease in this patient population. The study method is a randomized, double-blind , placebo controlled design. A sample of 50 patients with Type II diabetes and early to moderate periodontal disease will be recruited to be randomly assigned to a treatment (chlorhexidine gluconate 0.12% mouthrinse) or control (placebo mouthrinse) group, and stratified by diabetes control and periodontal disease status. Following dental cleaning and examination, subjects will be asked to use study mouthrinse twice a day for 6 months. During the 6 month duration of the study, subjects will be asked to return monthly to the clinic for a nurse interview and compliance, as well as at 3 month intervals for oral measurements, laboratory assessment (glycosylated hemoglobin) and dental prophylaxis. To date, 19 patients have completed the study. Data entry is in process, analysis will follow.